"I cannot help mentioning that the door of a bigoted mind opens outwards
so that the only result of the pressure of facts upon it is to close it more snugly."- Ogden Nash

This page relates to the Astronomy Picture of the Day
for 7th December 2004, which shows an unusual streak and flash on a daylight photograph. Many varied suggestions
have been made as to the cause, ranging from meteors and exploding lamps through to shadows and insects flying in
front of the lens. Viewers were challenged to find an explanation for the image; in order to help determine the
most likely explanation, this page presents a collection of results obtained both by applying various signal processing
techniques to the image in question and by physical experimentation.

Click images for larger versions

The image on the left shows just part of the original, and the trail can just be seen travelling from the upper left
corner to the lower right. By comparison the image on the right is a processed version of the full picture which reveals
the trail (and the object at the end of it) in more detail. It's evident from the procesed version that the trail both
starts and ends within the image, which tends to exclude a lot of explanations (in particular, it excludes the meteor
theory since the speed of a meteor is such that it would have crossed the whole frame during the exposure).

One of the explanations was that an insect, possibly a bee, either flew or was blown past close to the camera during
the exposure. Because it was close to the lens, it left a long trail behind it as a result of motion blur. This seemed
a reasonable explanation, and this theory was used as a guide in deciding what experiments and tests to make.